1. Field of the Invention
The present invention relates to a polymer electrolyte, a preparation method for the same, and a lithium battery using the same, and more particularly, to a polymer electrolyte having good ionic conductivity at room temperature and good mechanical properties, and a lithium battery using the polymer electrolyte.
2. Description of the Related Art
Since it is known in the art that polymer electrolytes exhibit high ionic conductivity at room temperature, polymer electrolytes have been used as electrolyte materials for a variety of kinds of electrochemical batteries. In addition, various kinds of research have been actively carried out into polymer electrolytes having good conductivity characteristics at room temperature. The research has focused mostly on plasticized polymer electrolytes containing a liquid electrolyte. The plasticized polymer electrolytes are prepared by adding a large amount of the liquid electrolyte into a polymer matrix. The plasticized polymer electrolytes are known to substantially contribute to making lithium polymer batteries practical.
In the above-described gel polymer electrolyte, usable polymer matrices that form polymers include curable polymers based on polyethylene-glyco-di(meth)acrylate, polyacrylonitrile, polyethyleneoxide, poly(methyimethacrylate) and combinations thereof. Examples of these polymer electrolytes disclosed are as follows. U.S. Pat. No. 4,908,283 discloses a polymer electrolyte prepared by curing a composition comprising acryloyl-denatured polyalkylene oxide. U.S. Pat. No. 4,792,504 describes a polymer electrolyte comprising polyethylene glycol dimethacrylate/polyethylene oxide. Japanese Patent Publication No. showa 63-94501 discloses a polymer electrolyte comprising acryloyl-denatured polyalkylene oxide and an inorganic salt and cured by actinic radiation. Also, U.S. Pat. No. 4,830,939 discloses a method of preparing plasticized polymer electrolytes by mixing polyethylene glycol dimethacrylate and liquid electrolyte and curing the same.
However, the polymer electrolytes prepared by the above-described methods are poor in mechanical strength while having good ionic conductivity characteristics.